title: Squamous cell carcinoma originating in the parotid gland: MRI features with histopathological correlation.
abstract: OBJECTIVE
  To report the magnetic resonance imaging (MRI) and corresponding histopathological features of squamous cell carcinoma (SCC) originating in the parotid gland.
  
  
  METHODS
  The MRI images of seven patients with histopathologically proven SCC originating in the parotid gland were reviewed retrospectively, with an emphasis on tumour size, shape, contour definition, extraparotid infiltration, signal characteristics, and the presence of central necrosis. These were correlated with the microscopic findings of the surgical specimens.
  
  
  RESULTS
  The tumours ranged in size from 3.9-7 cm (mean 4.7 cm). All tumours had an ill-defined margin with extraparotid infiltration, which seemed to reflect the invasive growth of the tumour cells on histopathological examination. The solid portions of the tumours showed predominantly low to intermediate signal intensities on T2-weighted images, which seemed to reflect the high cellularity, intercellular bridges, and/or keratin pearl formation observed at histopathological examination. Five of the seven tumours had central necrosis.
  
  
  CONCLUSIONS
  A relatively large tumour with central necrosis is a useful imaging feature of SCCs originating in the parotid gland, in addition to the well-recognized indicators of parotid malignancy, such as an ill-defined margin, extraparotid infiltration, and low to intermediate signal intensity on T2-weighted images.
authors.affiliation: Department of Radiology, Kinki University, Faculty of Medicine, Osaka-Sayama, Japan. Electronic address: hiroto.takahashi07@gmail.com.
authors.forename: H
authors.initials: H
authors.lastname: Takahashi
authors.affiliation: Department of Radiology, Kinki University, Faculty of Medicine, Osaka-Sayama, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Kashiwagi
authors.affiliation: Department of Pathology, Kinki University, Faculty of Medicine, Osaka-Sayama, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Chikugo
authors.affiliation: Department of Diagnostic Radiology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nakanishi
authors.affiliation: Department of Pathology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Tomita
authors.affiliation: Department of Radiology, Kinki University, Faculty of Medicine, Osaka-Sayama, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Murakami
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010307:Parotid Neoplasms / Q000175:diagnosis* / Q000473:pathology; D012189:Retrospective Studies